1. Field
Exemplary embodiments of the present invention relate to a semiconductor design technology, and, more particularly, to a semiconductor device capable of performing a calibration.
2. Description of the Related Art
Data is transmitted between the constituent devices of a system via a bus. The data transmitted via the bus is digital data, which is represented by “1 (high)” and “0 (low).” An electric device recognizes the data by analyzing the combinations of “0” and “1” in a transmitted data signal.
An electric device uses a reference voltage VREF to determine if the received signal is a “1” or “0.” When the voltage of a received signal is higher than the reference voltage, the electric device recognizes the signal as “1,” and when the voltage of the received signal is lower than the reference voltage, the electric device recognizes the signal as “0.”
The value of the reference voltage is generally not optimized because the reference voltage is inputted from an external source. In order to optimize the value of the reference voltage, a memory controller unit (MCU) has to perform a write/read operation. However, it is difficult and time consuming to optimize the value of the reference voltage for each pin.